perf tools: Implement counter output multiplexing
Finish the -M/--multiplex option implementation:
- separate it out from group_fd
- correctly set it via the ioctl and dont mmap counters that
are multiplexed
- modify the perf record event loop to deal with buffer-less
counters.
- remove the -g option from perf sched record
- account for unordered events in perf sched latency
- (add -f to perf sched record to ease measurements)
- skip idle threads (pid==0) in latency output
The result is better latency output by 'perf sched latency':
-----------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms |
-----------------------------------------------------------------------------------
ksoftirqd/8 | 0.071 ms | 2 | avg: 0.458 ms | max: 0.913 ms |
at-spi-registry | 0.609 ms | 19 | avg: 0.013 ms | max: 0.023 ms |
perf | 3.316 ms | 16 | avg: 0.013 ms | max: 0.054 ms |
Xorg | 0.392 ms | 19 | avg: 0.011 ms | max: 0.018 ms |
sleep | 0.537 ms | 2 | avg: 0.009 ms | max: 0.009 ms |
-----------------------------------------------------------------------------------
TOTAL: | 4.925 ms | 58 |
---------------------------------------------
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 3e00323..2ce87ef 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -116,6 +116,8 @@
static u64 run_avg;
static unsigned long replay_repeat = 10;
+static unsigned long nr_timestamps;
+static unsigned long unordered_timestamps;
#define TASK_STATE_TO_CHAR_STR "RSDTtZX"
@@ -1109,8 +1111,11 @@
if (atom->state != THREAD_SLEEPING)
return;
- if (atom->sched_out_time > timestamp)
+ nr_timestamps++;
+ if (atom->sched_out_time > timestamp) {
+ unordered_timestamps++;
return;
+ }
atom->state = THREAD_WAIT_CPU;
atom->wake_up_time = timestamp;
@@ -1130,6 +1135,11 @@
if (!atom_list->nb_atoms)
return;
+ /*
+ * Ignore idle threads:
+ */
+ if (!atom_list->thread->pid)
+ return;
all_runtime += atom_list->total_runtime;
all_count += atom_list->nb_atoms;
@@ -1301,8 +1311,16 @@
}
printf("-----------------------------------------------------------------------------------\n");
- printf(" TOTAL: |%9.3f ms |%9Ld |\n",
+ printf(" TOTAL: |%9.3f ms |%9Ld |",
(double)all_runtime/1e6, all_count);
+
+ if (unordered_timestamps && nr_timestamps) {
+ printf(" INFO: %.2f%% unordered events.\n",
+ (double)unordered_timestamps/(double)nr_timestamps*100.0);
+ } else {
+ printf("\n");
+ }
+
printf("---------------------------------------------\n");
}
@@ -1667,12 +1685,13 @@
"-a",
"-R",
"-M",
- "-g",
+ "-f",
"-c", "1",
"-e", "sched:sched_switch:r",
"-e", "sched:sched_stat_wait:r",
"-e", "sched:sched_stat_sleep:r",
"-e", "sched:sched_stat_iowait:r",
+ "-e", "sched:sched_stat_runtime:r",
"-e", "sched:sched_process_exit:r",
"-e", "sched:sched_process_fork:r",
"-e", "sched:sched_wakeup:r",